Bivalent transition metal complexes of 3-(2-(4-(dimethylamino)benzylidene)hydrazinyl)-3-oxo-N-(thiazol-2-yl)propanamide: Structural, spectral, DFT, ion-flotation and biological studies

• Synthesis of Co(II), Pb(II), Hg(II) and Cd(II) complexes.
• Spectroscopic characterization by 1H NMR, IR, UV–visible, MS.
• Studying the geometry of isolated solid compounds by DFT method.
• Studying the biological activity of the investigated compounds.
• Cd(II) and Pb(II) metals were separated from aqueous solutions using flotation method.

Co(II), Pb(II), Hg(II) and Cd(II) complexes of the 3-(2-(4-(dimethylamino)benzylidene)hydrazinyl)-3-oxo-N-(thiazol-2-yl)propanamide (H2L) were synthesized. The prepared compounds were interpreted by elemental analysis: C, H, N, M, Cl; physical measurements as molar conductance; and magnetic susceptibility spectroscopic techniques as IR, UV–visible, 1H NMR, MS spectra. The computational studying was estimated to approve the geometry of the isolated solid compounds. Also, Pb(II) and Cd(II) were separated using a simple, rapid and inexpensive quantitative flotation method prior to their determinations using atomic absorption spectrophotometric (AAS). The main parameters influencing the flotation process were examined (ca. initial pH, metal ion, surfactant and ligand concentrations, presence of foreign ions, and temperature). Furthermore, the biological activity (antimicrobial, anti-oxidant and cytotoxic) of the investigated compounds was tested.